In a contentious Senate hearing, Trump’s top law enforcement officer called Russiagate allegations “scurrilous” and said he has been the victim of a smear campaign.

WASHINGTON, DC - JUNE 13: U.S. Attorney General Jeff Sessions testifies before the Senate Intelligence Committee on Capitol Hill June 13, 2017 in Washington, DC. Sessions recused himself from the Russia investigation and he was later discovered to have had contact with the Russian ambassador last year despite testifying to the contrary during his confirmation hearing. (Photo by Chip Somodevilla/Getty Images)

Attorney General Jeff Sessions angrily denied on Tuesday ever colluding with Russian operatives in their campaign to meddle in the 2016 election. But in a heated, at times contentious hearing before the Senate Intelligence Committee, Sessions repeatedly refused to answer questions about his conversations with President Donald Trump while offering no discernible legal justification for doing so.

Sessions’s eagerly awaited testimony came just a week after ousted FBI Director James Comey told the same panel that Trump, whom he called a liar, had asked for personal loyalty and privately urged the FBI boss to clear a former White House official then under investigation, before eventually firing Comey.

On Tuesday, Sessions got his crack at addressing the snowballing allegations of Russian collusion with the Trump campaign to tip last year’s presidential election. The former Alabama senator denounced claims that he aided the Russian campaign, which saw hackers break into Democratic Party computer systems and leak their contents online, calling those allegations “an appalling and detestable lie.”

But the investigation has settled like a cloud over the White House, overshadowing even Trump’s stalled domestic agenda and disastrous foreign trip. The investigation is now being led by a special counsel, former FBI Director Robert Mueller. On Monday, a friend of Trump said that the president was considering firing Mueller. In separate testimony on Capitol Hill on Tuesday, Deputy Attorney General Rod Rosenstein, who aloneretains the power to fire Mueller, vowed to defend the integrity of the investigation.

Sessions has recused himself from that investigation, even though he took a personal hand in Comey’s firing, which Trump said was directly related to the Russia investigation.

In one of the most intriguing moments of Comey’s testimony last week, the former FBI chief said he was hesitant to fully discuss with Sessions his interactions with Trump, because he knew that Sessions would soon be recusing himself from the investigation. Comey said he couldn’t discuss in an unclassified setting why he believed Sessions should not be involved in an investigation dealing with Russia.

Asked about the comment on Tuesday, Sessions described it as a smear campaign against him.

“This is a secret innuendo being leaked out there about me, and I don’t appreciate it,” he said.

Much of Tuesday’s testimony centered on why Trump decided to fire Comey — the official Department of Justice version is at odds with the president’s televised explanation — but Sessions refused to describe his conversations with Trump on the issue.

Sessions said that Trump had not invoked executive privilege — the legal doctrine that the president enjoys some confidentiality in communications with advisors — to muzzle the attorney general. Yet Sessions still refused to answer lawmakers’ questions, saying that it would not be “appropriate.”

Sessions said he refused to answer questions on Tuesday in order to maintain Trump’s ability to assert executive privilege at some later date.

“I am protecting the right of the president to assert it if he chooses,” Sessions said.

That response drew outrage from Democratic senators, with Sen. Martin Heinrich (D-N.M.) accusing Sessions of obstructing a congressional investigation. The Senate Intelligence Committee, like its House counterpart, is carrying out a wide-ranging investigation of the Russian campaign to influence the 2016 election.

The White House first justified Comey’s dismissal by arguing that Comey acted inappropriately by publicly revealing the outcome of the FBI’s investigation of Hillary Clinton’s use of a private email system last summer, during the presidential campaign. But in a subsequent interview with NBC, Trump said that he when he decided to fire Comey he told himself, “This Russia thing with Trump and Russia is a made-up story.”

Critics of Sessions have questioned why the attorney general was involved in Comey’s firing when he had recused himself from the bureau’s investigation of Russian meddling. Sessions provided Trump with one of the memos they used to justify Comey’s firing.

On Tuesday, Sessions defended his role. “It is absurd, frankly, to suggest that a recusal from a single specific investigation would render an attorney general unable to manage the leadership of the various Department of Justice law enforcement components that conduct thousands of investigations,” he said.

As FBI and congressional investigators have examined the Russian operation to boost Trump’s 2016 electoral prospects, Sessions has emerged as a central figure as a result of undisclosed meetings with Russian Ambassador Sergey Kislyak. Press reports have identified at least two meetings between Sessions and Kislyak in 2016.

A third such meeting may have occurred on the sidelines of a foreign-policy speech Trump delivered in Washington, but Sessions — as he did dozens of times Tuesday in answer to all sorts of questions — said he “could not recall” whether he met with Kislyak at the event.